Below we learn about how much a catty of crab fry is generally and what are the characteristics of river crab reproduction.
China has a long history of eating crabs, and now the market is good.
Nowadays, crab seedlings are generally generally in the range of 13.5 yuan to 30 yuan a catty, a catty of about 80, which works out to be 0.17 yuan to 0.35 yuan a piece.
The crabs are so resilient that they can survive on their own when thrown into urban rivers. The crabs spend most of their time looking for food, and they're generally not picky eaters, as long as the chelonia can get their hands on any food.
Small fish and shrimp are their favorites, though some crabs eat seaweed and even dead animals and plants.
Of course, if the water is not clean and polluted, it certainly won't work.
The embryonic development of river crabs and the development of flea-like larvae are very sensitive to external conditions, especially to the ion concentration in the water, temperature, dissolved oxygen, current status, bait organisms and other strict requirements.
The river crab in nature in order to meet the needs of its larval development, every year at the end of autumn and early winter in the river fattening river crabs will have to swim to those suitable for the development of the crab embryo and flea-like larval development of the conditions of the river and the sea, that is, what people call the reproductive migration.
The river and sea confluence of water temperature is stable high and low suitable, slow current, the water is rich in nutrient salts, calcium, magnesium, potassium, sodium, chloride ions, sulfate, carbonate, etc. lower than seawater is higher than the freshwater, microelements are also very rich, with the double characteristics of seawater and freshwater, water capacity, unlike the rivers and lakes are easy to follow the changes in rainfall.
After arriving at the confluence of the river and the sea, the parent crabs are very excited because they have found a place with suitable breeding conditions.
Shortly afterward, they will mate and hold eggs to reproduce their offspring.
The embryonic development of the river crab and the flea-like larvae that moult five times to become big-eyed larvae (crab fry) are spent in a semi-saline environment.
Because of the strict environmental requirements for the development of river crab larvae, only a few places in China produce natural crab fry, according to the investigation of the northern and eastern coasts of Chongming Island at the mouth of the Yangtze River is now a better natural breeding ground for river crabs in our country, and a certain number of crabs clutching the eggs can be caught in the winter every year in the surroundings of Chongming Island, Hengsha Island and Changxing Island.
Every year in June at the mouth of the Yangtze River there will be crab seedlings just with the climate rainfall amount of river water runoff different abundance and failure.
Other places such as the mouth of the Oujiang River in Zhejiang Province, the mouth of the Qiantang River, the mouth of the Pearl River in Guangdong Province, the mouth of the Minjiang River in Fujian Province, and the mouth of the Liaohe River in Liaoning Province also have a certain amount of crab seedlings.
The amount of crab seedlings varies with the amount of parent crabs, freshwater flow, water temperature, light, salinity, wind direction, tidal current, the amount of bait organisms and human factors in various places in the year, such as in case of inclement weather, gusty winds and angry tides will be holding the eggs of crab damage or change the tide, the tiny crab seedlings drifting with the current to the distant sea loss, man-made fishing for parent crabs or factories on the pollution of the water quality and so on, affecting the production of crab seedlings.